The quick answer: Not recommended. Small amounts of lemon would likely not cause harm to your dog but consuming this fruit can cause gastrointestinal distress.
Benefits of lemons
Consisting mostly of water, these cheery, sour yellow fruits are a great source of vitamin C. Lemons are low in calories and contain potassium, antioxidants and dietary fiber. Though these health benefits are great for people, dogs that eat a balanced dog food will get all the nutrients they need and do not need to eat lemons for the health benefits.
If you are looking to share fruits or vegetables with your dog, there are many other palatable, nutritious options that your dog is more likely to enjoy, such as apples, bananas, cucumbers, or carrots.
Natural pest repellent
Though lemons aren’t particularly necessary for dogs to eat, they are beneficial when it comes to repelling fleas and ticks. Lemon juice is a common ingredient in all-natural and homemade pest repellents for dogs and cats because it can keep bugs away without the use of toxic chemicals. Though lemon spray doesn’t kill bugs, it is thought that the scent works as a disguise to bugs that are attracted to certain smells, like your pet’s exhaled breath.
Hazards to eating lemons
Lemons contain citric acid which in large quantities can be too much for your dog’s digestive system. Eating too much lemon can cause upset stomach, vomiting, and diarrhea. Though most dogs will likely not seek out lemons to eat, it’s a good idea to keep lemons out of reach from “garbage disposal” dogs that will eat anything.
The seeds and peel of a lemon could also pose a choking hazard for some dogs. If swallowed, the lemon peel could cause an internal blockage because it is difficult to digest, especially for smaller dog breeds.
Lemon juice, lemon zest, and the fruit itself may be touted for human health benefits, but the cons far outweigh the pros when it comes to your pet. Lemonade should also be kept off-limits for dogs because it contains added sugars which are unhealthy for them.